Dionysus is the god of the grape-harvest, winemaking and wine, of fertility, ritual madness, religious ecstasy, and theatre in ancient Greek religion and myth.

He is also known as Bacchus, the name adopted by the Romans and the frenzy he induces is bakkheia. His thyrsus, sometimes wound with ivy and dripping with honey, is both a beneficent wand and a weapon used to destroy those who oppose his cult and the freedoms he represents. As Eleutherios ("the liberator"), his wine, music and ecstatic dance free his followers from self-conscious fear and care, and subvert the oppressive restraints of the powerful. Those who partake of his mysteries are believed to become possessed and empowered by the god himself.

In his religion, identical with or closely related to Orphism, Dionysus was believed to have been born from the union of Zeus and Persephone, and to have himself represented a cthonic or underworld aspect of Zeus. Many believed that he had been born twice, having been killed and reborn as the son of Zeus and the mortal Semele. In the Eleusinian Mysteries he was identified with Iacchus, the son (or, alternately, husband) of Demeter.

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